Clearly define your goal (a question you want to answer, hypothesis you want to test, prediction you want to make) - as precisely as possible
Design or Select your model
Implement the model
Evaluate the model and quantify uncertainty
Apply the model to the goal
Communicate model results
What are your inputs-outputs?
What’s in the box (the model itself) that gives you a relationship between outputs and inputs?
Inputs: Varying; think x of a x vs y regression
Parameters: single values that influence relationships in the model
Transfer Function (model): Equations that transfer inputs to outputs given parameters
Outputs: what you want to estimate
What are the processes/relationships that you think are important to translate inputs to output
Transfer function (mathematical representation)
Parameters, values that influences how the model relationships work
There are often multiple “boxes” internal to a model
Input: Change in unemployment rate
Output: Change in GDP
Parameters: Slope and intercept of the line The US “changes in unemployment – GDP growth” regression with the 95% confidence bands.
Transfer function: regression equations
Often more complicated than a simple regression…
So we need to think through what the relationships are; the processes are that we want to take in to account
Conceptual models are a good place to start
How will coral reefs change in the next decade given increased CO2
Input: Solar energy and atmospheric CO2, land DIC,
Output: Reef Dissolution, DOC/DIC export
Parameters: Many parameters that would be part of equations that estimate photosynthesis, calcification etc
Modeling changes both the changes in seawater chemistry in coral reef waters, as well as the responses of reef organisms.
Precipitation = Evapotranspiration + Change in Storage
P = ET + ΔS
(at global scales ΔS includes streamflow since that water is still “stored” in the earth
Goal - estimate streamflow fromm multiple source (surface and subsurface)
More complex model couple sub-models
How do ecological and human factors interact to influence fire regimes